Recent years have witnessed an upsurge in prisoners' protest. In contrast to earlier times, such militancy has increasingly been channelled into collectivised and controlled strikes and demonstrations. There has been an accompanying change in both the content and style of presentation of inmates' demands, reflected in the explicitly political rhetoric of their 'manifestoes'. This dissertation is concerned with one feature of this 'new' militancy - prisoners' attempts to organise themselves to protest not only about the material conditions, but also about the fact of their incarceration. It looks in particular, at the emergence of Preservation of the Rights of Prisoners (PROP), the British prisoners' union founded in May 1972. A comparative analysis with the movement in the USA is undertaken, and the whole thesis is informed by the work of Thomas Mathiesen, and the Scandinavian experiences. The first chapter presents a brief history of imprisonment to raise the question of why people are imprisoned. This leads into a discussion of more recent developments and possible future trends of British penal policy. Chapter Three outlines prison conditions, which, it is argued, provided much of the impetus for the emergence of PROP. Chapter Four provides a brief historical sketch of British prisoners protest. The section on PROP is largely documentary, and is based upon my own direct involvement in the movement as a founder member, and press officer of the union. The sixth chapter highlights some of the issues raised by PROP, by using comparative material from the USA. The concluding chapter seeks to draw out the main obstacles confronting an emergent prisoners' organisation and places it firmly in the political sphere.